This is part of a consultation on the Red List implications of extensive changes to BirdLife’s taxonomy for non-passerines

Lynx Edicions and BirdLife International will soon publish the HBW-BirdLife Illustrated Checklist of the Birds of the World, building off the Handbook of the Birds of the World series, and BirdLife’s annually updated taxonomic checklist.

The new Checklist will be based on the application of criteria for recognising species limits described by Tobias et al. (2010). Full details of the specific scores and the basis of these for each new taxonomic revision will be provided in the Checklist.

Following publication, an open and transparent mechanism will be established to allow people to comment on the taxonomic revisions or suggest new ones, and provide new information of relevance in order to inform regular updates. We are also actively seeking input via a discussion topic here regarding some potential taxonomic revisions that currently lack sufficient information.

The new Checklist will form the taxonomic basis of BirdLife’s assessments of the status of the world’s birds for the IUCN Red List. The taxonomic changes that will appear in volume 1 of the checklist (for non-passerines) will begin to be incorporated into the 2014 Red List update, with the remainder, and those for passerines (which will appear in volume 2 of the checklist), to be incorporated into subsequent Red List updates.

Preliminary Red List assessments have been carried out for the newly split or lumped taxa. We are now requesting comments and feedback on these preliminary assessments.

Pheasant Pigeon Otidiphaps nobilis is being split into O. nobilis, O. insularis, O. aruensis and O. cervicalis, following the application of criteria set out by Tobias et al. (2010).

Prior to this taxonomic change, O. nobilis (BirdLife species factsheet) was listed as Least Concern on the basis that it was not thought to approach the thresholds for Vulnerable under any of the IUCN criteria. This species was estimated to have a very large range, and hence did not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence [EOO] of less than 20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). The population trend appeared to be stable, and hence the species did not approach the thresholds for Vulnerable under the population trend criterion (at least a 30% decline over ten years or three generations). The population size has not been quantified, but it was not believed to approach the thresholds for Vulnerable under the population size criterion (fewer than 10,000 mature individuals with a continuing decline estimated to be at least 10% over ten years or three generations, or with a specified population structure).

O. insularis is restricted to primary forest on Fergusson Island (D’Entrecasteaux Islands) (del Hoyo et al. 1997, Gibbs et al. 2001). It is suggested that it qualifies as Endangered under criteria B1ab(ii,iii,v); C2a(ii), on the basis that it occupies a very small range (with an EOO estimated at 1,300 km2), in which its habitat is severely fragmented and declining; the species also appears to be rare and is likely to have a population of fewer than 2,500 mature individuals, forming a single subpopulation, which is inferred to be in decline owing to on-going habitat loss and degradation.

O. aruensis is endemic to the Aru Islands, where it occupies primary forest (del Hoyo et al. 1997, Gibbs et al. 2001). It is suggested that it qualifies as Vulnerable under criterion C2a(ii), on the basis that it is thought to number fewer than 10,000 mature individuals, probably forming a single subpopulation, which is inferred to be in continuing decline owing to habitat loss and degradation and suspected hunting pressure.

O. nobilis (as defined following the taxonomic change) occurs on Batanta, Waigeo and the mountains of western New Guinea, east to Nassau, whilst O. cervicalis occurs in eastern New Guinea; both species occupy primary forest, from lowland to montane areas (del Hoyo et al. 1997, Gibbs et al. 2001). O. nobilis and O. cervicalis are both likely to warrant listing as Least Concern, on the basis that they are not thought to approach the thresholds for Vulnerable under any of the IUCN criteria.

Comments on these suggested categories are invited and further information would be welcomed.

K. D. Bishop Field Notes:
Prof. Jared Diamond and I visited the Aru Islands (Papua, Indonesia) during 28 March – 12 April 1988 – “A number of natives described birds, often as a third megapode type that are consistent with this species.” We have no audial or visual records of this species ourselves from the Aru Islands.